Compressor critical speeds

[HamzaNossair]

Hi All:

I have a compressor supplier proposing 1500 mm shaft, 125 mm D, tilting pad compressor/ bearing system, runs at 9000 RPM, is it usual and acceptable to have 2 critical speeds below the operating speed and the 3rd above within undamped analysis, and when he run the damped analysis, only one critical speed is below the operating speed, which eliminate the situation of the undamped?

What about bearing loading?


And what about loading on or between pads?

 

[Tmoose]

Double posting is discouraged.
It can result in diluted responses too